Where to get parts to rebuild a 2 stroke?

[racefactory]

Hi there,

Got a TZR 250 91 standar R model and am doing my research on re builds now.

I want to do a top end soon. From what i hear, as long as you keep re building your top end thats the way to go.

But where can i get these parts for a TZR and does anyone know alternative parts that will fit it (i think some TZ250 parts fit a?) :
piston
rings
pin clips and wrist pin
gaskets
small end bearing

I am new to this and always see people on trademe saying ''oh, just had new rings, piston, , , '' , i would like to start doing this myself now. Also how many kms do you guys say between re builds?


Really appreciated,

Thanks.

[awayatc]

Dealership for original pistons and parts.....
And check out Wiseco for aftermarket pistons..often cheaper....

[idleidolidyll]

Hi there,

Got a TZR 250 91 standar R model and am doing my research on re builds now.

I want to do a top end soon. From what i hear, as long as you keep re building your top end thats the way to go.

But where can i get these parts for a TZR and does anyone know alternative parts that will fit it (i think some TZ250 parts fit a?) :
piston
rings
pin clips and wrist pin
gaskets
small end bearing

I am new to this and always see people on trademe saying ''oh, just had new rings, piston, , , '' , i would like to start doing this myself now. Also how many kms do you guys say between re builds?


Really appreciated,

Thanks.

The thing about 2 strokes is that its very common for the top end items to be the same or almost the same as other bikes and brands. Some Yammy pistons and rings work in KTM's etc.
2 strokes are cheap compared to 4 strokes to repair and particularly if you know enough to search around and find a match from several suppliers. The height from the gudgeon pin to the piston crown is as important as the piston diameter as is the gudgeon pin size. However, you can even change conrods between brands and that may mean you can use a complete upper assembly from a cheaper supplier now and into the future.
The skirt of the piston is where all the action happens really; it covers and uncovers the inlet and exhaust ports at the right time to get the best out of the engine. If you buy a longish skirt piston, you can usually cut that skirt down to match the standard piston's porting.

If you don't know what you're doing though, it'll run very badly. Just a millimeter difference in exhaust port opening will make a huge difference to your power delivery.

If you're in Auckland I recommend Gaudenz Gisler in Tuakau. He's in the white pages under that name and has a very good workshop setup not far from the Harrisville MX track.

BTW: On a 2 stroke you will have to recondition the crank assembly from time to time so make sure it's up to spec before doing just the top end.

[racefactory]

Thanks very much. I am enquiring at a few Wiseco places now.

Do you think it's best just to ask if they have a piston with x, x, x, measurements? If so what measurements?

[Taz]

Depends on how worn your bores are.

[idleidolidyll]

Yep,
your cylinders might be worn but from memory the TZR used nikasil coated bores. Generally those last a long time unless there is a seizure.
The piston and rings are designed to wear out long before the inside of the cylinder.
Definitely check them at least visually. If there are any ugly vertical scuffings, you'll need to have the cylinders bored and recoated.
If they are good I'd take the piston with me when going to look at others. You should be able to make a judgement on the spot but do take along at least a vernier caliper so you can make some measurements.
If you're not so sure, don't even do it yourself, get an expert on the job. 2 strokes are not that expensive as there are only 3 main moving parts in each cylinder: pison, crank and conrod. No valves to worry about, no springs, no cams etc

[racefactory]

thanks so much,

I am keen to take it for a first time, but how much are we looking at here very roughly? Really have no idea a...

Im in Auckland and have just phoned all the Yamaha dealers here. Hopefully theyll call me back with all the stuff but if not... i have no idea where people get their parts to do this really. I mean, its not exactly like you can just pick up a spare engine for parts at anytime.

Any info is good info right now.

Thank you again.

[quallman1234]

thanks so much,

I am keen to take it for a first time, but how much are we looking at here very roughly? Really have no idea a...

Im in Auckland and have just phoned all the Yamaha dealers here. Hopefully theyll call me back with all the stuff but if not... i have no idea where people get their parts to do this really. I mean, its not exactly like you can just pick up a spare engine for parts at anytime.

Any info is good info right now.

Thank you again.

Mmm depends, but probabaly in the region of 150 - 250 per pistion kit. So 300-500 for both. Save up?

[Skunk]

Places I use:

Yambits

RDLC crazy

Yamaha-rd

[geoffm]

Depending on th emodel, motoequipe (TonyB here) in Christchurch sells Japanese TKRJ psitons which are good.
Yamaha pistons are OEMed by ART - so go for ART psitons. Pro-X are good as well, and are my choice.
If you use Wiseco, watch the clearances, as they expand more and cold sieze. It was part of the reason my RG500 is now in 4 fishbins.
Geoff

[racefactory]

hey thanks guys.

Yes! I have been looking at prox. they seem good but i cant find a dealer on google in nz.

i need help with something tho: http://www.pro-x.com/downloads/Street%20Bike.pdf

please, can someone explain why it says TZR125/250 87-91. Do tzr125 and tzr250 really use same piston? And from 87- 91 youre telling me they are the same piston? The motor from 87- 91 went over 3 configurations so is it possible piston size could remain same?

get this. i called yamaha... they said each piston is 180, each ring is 100, clips 60, bearing 40, it was just insane. talking over 800 for a top end through yamaha.

I found a guy on ebay, i can get 2 top end rebuildkits with gaskets and gudgeon bearings too for 500NZ. not bad, but can do better still i think.

now i found some cheap pistons kits on this UK website, but can anyone tell me if they are any good? http://www.pjme.co.uk/acatalog/Onlin...7_1991_20.html

Ive been searching and i dont think wiseco make TZR250 pistons. ART dont do them and neither does TKRJ.

''mitaka'' i think the brand is on that box. If prox kits are really all the same for all years TZR, then i guess this one here will also fit my 3xv 91?

[Sellout]

Not too sure whether he would carry any new engine pieces, but Darryl from Japanese Motorcycle Dismantlers here in Chch in definitely worth talking to. He has moved out to his farm in Rangiora now, but still runs the 2nd hand parts & wrecker over the website, and with couriers these days... www.japmcdismantlers.co.nz

He has found fairing parts, gear lever, handlebars, oil pumps etc etc etc for my RZ and said he has a rather good collection of Yammie and 2 stroke stuff! Seriously, he has about 2 warehouses full of stuff, great for discontinued/ original parts.

[Ixion]

hey thanks guys.

Yes! I have been looking at prox. they seem good but i cant find a dealer on google in nz.

i need help with something tho: http://www.pro-x.com/downloads/Street%20Bike.pdf

please, can someone explain why it says TZR125/250 87-91. Do tzr125 and tzr250 really use same piston? And from 87- 91 youre telling me they are the same piston? The motor from 87- 91 went over 3 configurations so is it possible piston size could remain same?

get this. i called yamaha... they said each piston is 180, each ring is 100, clips 60, bearing 40, it was just insane. talking over 800 for a top end through yamaha.

I found a guy on ebay, i can get 2 top end rebuildkits with gaskets and gudgeon bearings too for 500NZ. not bad, but can do better still i think.

now i found some cheap pistons kits on this UK website, but can anyone tell me if they are any good? http://www.pjme.co.uk/acatalog/Onlin...7_1991_20.html

Ive been searching and i dont think wiseco make TZR250 pistons. ART dont do them and neither does TKRJ.

''mitaka'' i think the brand is on that box. If prox kits are really all the same for all years TZR, then i guess this one here will also fit my 3xv 91?

TZR125 = 1 cylinder. TZR250 = 2 cylinder . 125 * 2 = 250 . capiche ?

ART is the genuine Yamaha article. Usually only available through Yamaha agents.

Wiseco do make a TZR250 piston though maybe not ex stock. Problem with Wiseco, it's a forged piston, tends to cold sieze REAL easy. Unless your racing it, maybe more trouble than it's owrth

Mitaka is a well known third party piston. General opinion seems to be "its OK". There's a LOT of controvocy about whether to use the ring expander. Many folk claim extremely high cylinder wear when you do.(this ONLY applies to Mitaka)

TKRJ do a TZR125 lkit. 1 + 1 = 2. TKRJ are at least as good as Mitaka

With two strokes, there's pistons, and pistons. Arguments about pistons are to two smokers what arguments about tyres are to adventure riders. Cheap pistons can cost a LOT of money very quickly. Buy the best you can find.

Those prices look about right for genuine Yamaha goods. Excepot for circlips that's wrong, they're about $1.50 each, total about $4. If you can afford it , genuine is best.

Also, buy a genuine head gasket. This is not an area to scrimp on.

The RD350-RD400-RZ350 went through at least a dozen engine configs over about 20 years (if you count the Brazilians) but all the pistons are interchangeable, given a fit of fettling with Mr File. So four years is nothing.

(Incidentally that TZR125 has a claimed top speed of just on the ton. And the handling would be orgasmic, i'd say. Be a REAL nice bike)

[racefactory]

awesome info there mate.

hey i have just found what HAS to be the cheapest rebuild for a TZR 250:

ok, after reading and reading, searching and searching. ive found how to do this.

... yamaha TZ 250 pistons. Basically its a single ring piston. on the tzr message board, loads of guys are using these TZ250 pistons and they have been great.
...the best part.... I can get 2 pistons, 2 rings, circlips, 2 gudgeon bearings, 2 gudgeon pins, and 3 choices of base gasket all for 330NZ to my door. yamaha parts.

the TZ250 pistons are more race oriented with a single ring. That obviously wears out faster, so you need to replace the ring more often. Most guys seem to get new ones every 10 000km to be on the safe side, and as far as im concerned... thats a hell of a long time for me as far as im concerned. Overall that is still a lot cheaper than yamaha dealer as youre paying once for the lot and then after 10 000km replacing rings... another 10k or so and buy another kit (if i still have this bike by then). They also say there is sharper response with the lower friction of the single ring, and a very slight increase in power with the domed top and a choice of slightly thinner base gasket. also single ring is less likely to cause as much damage as a 2 ring if it does fail.

works out perfect for me anyway-

i will check out the mitaka tz125 piston set before though. i guess that will be a straight fit.

if any TZR owners want to know where to get these parts let me know.

hopefully this thread will provide other rebuild n00bs like me with a starting point.

cheers thanks.

[xwhatsit]

(Incidentally that TZR125 has a claimed top speed of just on the ton. And the handling would be orgasmic, i'd say. Be a REAL nice bike)

O/T: I very very nearly bought one as my first bike instead of the 250RS. Cheap as chips -- less than $1800 I think. It wasn't registered in NZ, it was an import, so I stayed away. Not long afterwards, it turned up on Trademe as a crashed wreck -- seized mid-corner